Construction of dry surface contact rectifiers and the like



J. M. J. DORMOY El AL 2,213,388

CONSTRUCTION OF DRY SURFACE CONTACT RECTIFIERS AND THE LIKE Sept. 3, 1940.

Filed Nov. 2, 1938 INVENTORS JulesMarze Joseph, Dapmoy.

BY Rog'er- Doucaz. a-zudlu THEIR ATTORNEY Patented Sept. 3, 1940 PATENT OFFICE CONSTRUCTION OF DRY SURFACE CON- TACT BECTIFIE'RS AND THE LIKE Jules Marie Joseph Dormoy, Paris, and Roger Doncot, Livry-Gargan, France, assignors, by mesne assignments, to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application November 2, 1938, Serial No. 288,428 In France June 30, 1938 zoni (01. 125-366) This invention relates to uni-directional current carrying devices of the dry surface contact type now widely utilised for rectifying alternating electric currents and other analogous purposes.

The invention more particularly relates to devices of this character comprising one ormore elements each consisting of a support or base plate composed of a metal or metalloid on one or both faces of which a layer of a substance (usum ally a compound of tne metal or metalloid) is formed in any suitable manner, this layer'in conjunction with the plateconstituting an asymmetrically conducting element.

The plate or disc and the layer orlayers above referred to constitute the electrodes of the element which may also comprise one or more additional electrodes interposed between the plate or disc and the outer surface of the layer or layers.

The invention has for its object to provide improved arrangements whereby the several electrodes of an element of the character above described may be simply and conveniently electrically connected to suitable electrodes of other elements or, to an external circuit and according to the principal feature of .the invention each element is provided with an aperture or set of apertures for each electrode to be connected, each of these apertures being provided with and serving as a guide for an annular connector member which is electrically connected in any suitable manner to the appropriate electrode of the element.

The invention is illustrated by way of example in the accompanying drawing of which Fi ure 1 35 is a sectional view of a two electrode rectifier element showing the first stage in the application to the element of a connector device in accordance with one form of the invention.

Figure 2 is a sectional view similar to Figure 1 showing the element completed and ready for assembly with other elements, Figure 3' being a plan view of one half of the contact member utilised in the element shown in Figure 2. Figures 4 and 5 are transverse sectional views on the lines- IV-IV and V- V, respectively of Figure 3.

Referringnow to the drawing, it will be seen that the element comprises a metal plate I which may be of rectangular form, provided with two apertures namely one for each electrode. The

plate I which is composed of copper, for instance, is provldedon each face with a layer 2 of a suitable substance, for example, cuprous oxide sothat the plate I in conjunction with the layers 2 form an asymmetric element of the well known dry surface Contact type.

Annular zones of the layers 2 surrounding one of the apertures viz the right hand aperture in.

: Figures 1 and 2, are removed by grinding or in any other suitable manner and a short sleeve or tube 3 composed of relatively soft metal such as 5 copper or brass is inserted into the aperture and electrically connected and secured to the plate I at this point in any suitable-manner as for instance by deforming the sleeve 3 so as to form flanges g pping the edge of the aperture in the '10: plate I as shown in Figure l.

The outer face of each of the layers 2 is provided, as is usual, with a thin metal coating (not shown) applied to or formed upon the surfaceof the layer in any suitable known manner and a '1. bridge piece 5 is applied to each of the metalcoated surfaces. Each of the bridge pieces 5 is of the form shown in Figures 3, 4, and 5 and is composed of sheet metal having a relatively high electrical conductivity, end with an aperture of somewhat greater diameter than the corresponding aperture in the plate I. interposed between each bridge piece 5 and the adjacent metal-coated surface of the layer 2 is an annular washer 4 of relatively soft metal such as lead which ensure good electrical contact between these surfaces and the bridge piece 5.

The apertures in the bridge pieces 5 surrounding the sleeve 3 are provided with annular insulating bushings 6 between each of which and the sleeve 3 a metal bearing bushing I is interposed and these various partsvhaving been placed in position, the outer ends of the sleeve 3 are turned over so as to clamp the parts firmly together.

It will be understood that by this construction the sleeve 3 is electricallyconnected to and forms a connector member for the plate I while the bridge pieces 5 are electrically connected to the layers 2 through the washers '4.

In the other aperture in the plate I is inserted, 40 a sleeve 9 of relatively soft metalfsimilar to the sleeve 3 and surrounded by an insulating bushing 1.. Lead washers l are interposed between the bridge pieces 5 and the metal-coated surfaces of the layers 2 and the outer ends of the sleeve 9 ,5 are provided with spacer washers 3 over 'which these ends are turned over so as to clamp the parts securely together. The spacer washers 8 are of such axial dimensions that the turned over ends of the sleeves 3 and 3 on each side .of the, plate I lie in a plane parallel to the plane of the I plate. I

The intermediate portion of each of the bridge pieces 5 is formed withdateral tongues ,or projections II which assist ir nsuring an even and is provided at each 30 bearing of the bridge pieces 5 on the sort metal washers 4. I

The assembly in apile or column of a number of two-electrode elements constructed as above described is effected by means of insulated bolts or rods passing through the sleeves 3 and 9 and secured to suitable end plates or members, and it will be understood that when thus assembled the ends of the sleeves 3 and 9 of one element abut against the corresponding sleeves of the next adjacent element so as to effect the necessary electrical connections between the electrodes of these elements. If, for example, it is required that the several elements should be connected in parallel with one another, the elements will be so assembled that their sleeves 3 all surround the same bolt or rod while the sleeves 9 of all the elements surround the other bolt or rod. The sleeves ii of all the elements are thus electrically connected and form one terminal of the composite device while the sleeves 9 of all the elements are electrically connected and constitute the other terminal.

If on the other hand it is required that two adjacent elements should be connected in series with one another the elements are assembled upon the rods or bolts so that the sleeve 3 of one element is opposite to the sleeve 9 of the next adjacent element, a washer of electrically conducting material being interposed between these sleeves. The sleeve 9 of the first element will thus be opposite the sleeve 3 of the other element and an insulating washer isinterposed between these sleeves. The sleeve 3 of one element will thus effect an electrical connection from the plate l of one element to the layers 2 of the other element through its sleeve ii.

By thus reversing the position of alternate elements of the pile or column, all the elements can evidently be connected in series or by reversing only certain elements any desired seriesparallel connection of the elements can be effected.

The sleeve 3 which as above described constitute connector members for the plates 1! may if desired be secured to the plates otherwise than by deforming the sleeves or may even be replaced by annular projections formed on the plates themselves if desired.

In the case of elements comprising more than two electrodes, each element is provided with a corresponding number of apertures or sets of apertures having connector arrangements similar to those above described and it will be understood that the bridge pieces provided for the electrodes other than the plate must be of such form as to be suitably insulated from one another.

In order to effect the necessary connection to tion.

an external circuit or circuits, suitable sheet metal connectors may be provided mounted upon the rods or bolts in a similar manner to the elements and adapted to engage with the appropriate sleeves of these elements.

Although we have herein shown and described only one form of rectifier embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our inven- Having thus described our invention, what we claim is:

1. In combination, a metallic plate provided with a pair of apertures and on one side with a layer of a substance which in conjunction with the plate constitutes an asymmetric conductive element of which the plate and layer form electrodes, a first conducting sleeve passing through one of said apertures and secured to said plate for effecting electrical contact therewith, a second sleeve passing through the other aperture and insulated therefrom, a bridge piece electrically connected with said layer and provided lit with apertures which receive said two sleeves with clearance, and means for insulating said bridge piece from said one sleeve and electrically connecting it with said other sleeve. 7

2. In combination, a metallic plate provided with a pair of apertures and on each side with a layer of a substance which in conj ction with the plate constitutes an asymmetric conductive element of which the plate and layer form electrodes, a first conducting sleeve disposed in one of said apertures and secured to said plate for making electrical contact therewith, a second conducting sleeve disposed in the other aperture and insulated from said plate,

two bridge pieces disposed on opposite sides of said plate and each provided with two apertures which receive said sleeves with clearance, a conducting washer surrounding each of said sleeves on each side of said plate between the associated bridge piece and the associated layer and establishing electrical connection between said bridge pieces and the associated layers, an annular insulating bushing surrounding said one sleeve on each side of said plate and extending into the adjacent aperture in each bridge piece, a metal bushing fitting into each insulating bushing, the outer ends of said one sleeve being bent over to hold the parts in place, and spacer washers disposed on the outer ends of said other sleeve, said other sleeve having its ends bent over these washers to hold the parts in place. 

